A semiconductor photodiode array generates non-equilibrium carriers to detect incident light by generating visible light in the scintillator through direct incident light or X-ray, which may cause ionization reaction with atoms in the semiconductor. Key parameters for measuring the performance of a photodiode array include resolution, signal-to-noise ratio, readout speed, and inter-pixel charge crosstalk etc. In addition, the charge collection uniformity of active regions for collecting dark current and light inside single pixel is also of particular importance.